Gas flow control louvres



-ot.,1'0', 1967 I a t cm 3,346,007-

7 Gas FLOW CONTROL LOUVRES Fil ed Aug. 15, 19s: I Y 2 Sheets-Sheet 1 I lrwenlor SHMUEL A GNON v A ttorneys @ZWZM" Oct. 10,1967 YS.AGNON 3,345,007

GAS now CONTROL LOUVRES Filed Aug. 15, 1963 2' Sheets-Sheet'z lnvenlo d Q New A llomeys United States Patent 3,346,007 GAS FLOW CONTROL LOUVRES Shmuel Agnon, Haifa, Israel, assignor to The State of Israel, Ministry of Defence, Hakiria, Tel Aviv, Israel Filed Aug. 15, 1963, Ser. No. 302,325 Claims priority, application Israel, Aug. 22, 1962, 17,838 2 Claims. (Cl. 137--512.1)

This invention relates to gas flow control louvres of V the kind having a plurality of pivotal slats which pivot into an open position under the pressure of through flowing gas and which returns to a closed position when the pressure of the gas falls below a pre-determined minimum level. Such louvres will hereinafter be referred to as gas flow control louvres of the kind specified.

With such control louvres considerable difiiculty is experienced in ensuring that the louvre c'loses tightly when the pressure of gas has fallen below this minimum value. It is of a particular importance to ensure that such tight closing takes place so as to prevent any possible backfiow through the louvre of noxious or contaminated gases.

It is an object of the present invention to provide a new and improved gas flow control louvre of the kind specified in which the above mentioned difficulties are substantially overcome.

According to the present invention there is provided a gas flow control louvre of the kind specified wherein each slat is pivotable about an axis parallel to the longitudinal axis of the slat and displaced from the position occupied by the slats when closed, the edges of each slat being.

respectively associated with seatings against which they bear tightly when closed.

With such a control louvre in accordance with the invention the slats are normally biased into a closed position. This biasing can be effected directly by gravity or by some other mechanical means such as for example spring biasing. Irrespective of the form of biasing employed the fact that the slats are pivoted eccentrically ensures that, the biasing exerts on them a susbtantial force in the direction of closing.

The invention will now be described by way of example and with reference to the accompanying drawings in which:

FIG. 1 is a longitudinal sectional elevation of a vertically disposed control louvre in accordance with the present invention,

FIG. 2 is a cross-sectional elevation of a first form of horizontally disposed control louvre in accordance with the invention, and

FIG. 3 is a cross-sectional elevation of a second form of horizontally disposed control louvre in accordance with the invention.

As seen in FIG. 1 of the drawings a wall 1 has formed therein a ventilation opening 2 which is .adapted to be closed by means of a control louvre 3. The control'louvre comprises a plurality of elongated rectangular sl-ats 4. Each slat 4 is secured, at a spaced apart position thereof to ,a pair of pivoting brackets 5 (only one being shown). One end of each bracket 5 is bolted to a slat 4 whilst the other end is pivoted to a common control rod 6. Formed integrally with each bracket 5 and branching olf therefrom is a branch limb 7 the end of which is pivot-ally mounted on a web 8 of an elongated angle iron 9. Each angle iron 9 is secured at its end to a frame 10 of the aperture 2. The uppermost angle iron 9 is also secured to a bracket 11 which depends from the upper edge of the frame 10 of the aperture 2. Thus each slat pivots about an axis 7a which is parallel to the longitudinal axis of the slat but is spaced away from the position occupied by the slat when closed.

The edges of each slat 4 are provided with a suitable sealing strip 12 which bears against the seating provided by the'vertical limb of the angle irons 9 and the free limb of the frame 10.

A stop member 13 is disposed below the common control rod 6 and in the path thereof. This stop member is secured to a rotating lever 14 whose movement is controlled by a motor 15.

In use, the function of the control louvre is to allow the flow of gas (usually air) through the aperture 2 in the direction of the arrow 16 whilst preventing the backfiow of gas in the reverse direction. When the flow of air in the'direction of the arrow 16 exceeds a predetermined rate the slats 4 tend to pivot into an open position as shown by 4' in the drawings. Any movement of the slats is of course accompanied by movement of the control rod 3 and a downward movement of the control rod is limited by the position of the stop member 13 As shown in the drawings the position of the stop member 13 is such as to prevent any opening at all of the slats 4. The position of the stop member 13 is automatically varied by the motor 15 as a result of information fed to the motor concerning the requirements at ,any particular time for the -fiow of the gas in the direction 16. Thus, when conditions to the left of louvre are such as to require an increased flow of gas to the louvre the motor 15 automatically lowers the stop member 13 so as to allow for an increased degree of opening of the louvre. Conversely when a reduced or zero supply of gas is required the stop member is raised thereby tending to close the louvre. Thus the motor 15 and its associated stop member 13 operates to control automatically the degree of opening of the louvre. On the other hand, if at any time whilst the louvre is open the flow of gas thereto drops suddenly below a predetermined minimum the slats automatically fall back into their closed position. Furthermore, by virtue of the fact that the slats are eccentrically mounted the slats are firmly pressed with their sealing strips against the seatings provided by the vertical limbs of the brackets 9 and the tree limbs of frame 10. Thus it is ensured that the possibility of the flow of gas in the direction from left to right is substantially prevented.

In the arrangement shown in FIG. 2 of the drawings the louvre, which is substantially of the same construction as that shown in FIG. 1 is mounted horizontally. In this case too the slats are biased by gravity into a closed position, the degree of opening of slats being again controlled by a motor controlled stop member. As in the arrangement shown in FIG. 1 the eccentric mounting of each slat ensures that it bears tightly against its seating when closed.

In the arrangement shown in FIG. 3 however, the normal tendency of the slat is to open under gravity. In order to overcome this tendency the control rod is biased by a tension spring 21 against movement to the right, the effect of the tension spring therefore being communicated to the slats and urging them into a closed position as shown in the drawings. This biasing elfect of the spring is overcome by a throughflow of gas in the direction of the arrow. Again as in the case of the previous embodiment, by virtue of the eccentric mounting of the slats, the slats are firmly pressed against their seating under the influence of the biasing force.

3 I claim: 1. A gas flow control louvre comprising a flange having a plurality of openings, the periphery of each of said openings defining a seat, a plurality of pivotal slats adapted to pivot into an open position with respect to said openings under the pressure of through flowing gas and to return to a closed position when the pressure of the gas falls below a predetermined minimum level, each of said slats being pivotable about an axis parallel to the longitudinal axis of the slats and displaced from the position occupied by the slats when closed, the edges of each slat being respectively associated with seatings against which they bear tightly when closed, each of said slats having an actuating lever associated therewith, each of said levers having an arm secured at one end to an associated slat and extending outwardly therefrom forming an acute angle with respect thereto, said lever having a second arm secured ,at one end to said first arm and extending outwardly therefrom in direction at right angles to the associated slat when the latter is closed, the free end of said second arm being pivotally mounted to the frame to define the pivotal mount for the associated slat, a control rod'extending parallel to the frame, the free end of each of said first arms of said lever being pivotally connected to said control rod at spaced positions along its length and a displaceable abutment member in the path of movement of one end of said control rod to limit the movement of the latter.

2. A gas flow control louvre according to claim 1, wherein the displacement of said abutment is effected by means of a motor.

References Cited UNITED STATES PATENTS 1,099,689 6/1914 Broadhurst et al. 137-512.1 X 1,588,445 6/1926 Chandler 25l287 X 3,123,098 3/1964- Bishop 137601 WILLIAM F. ODEA, Primary Examiner.

D. I. ZOBKIW, Assistant Examiner. 

1. A GASL FLOW CONTROL LOUVRE COMPRISING A FLANGE HAVING A PLURALITY OF OPENINGS, THE PERIPHERY OF EACH OF SAID OPENINGS DEFINING A SEAT, A PLURALITY OF PIVOTAL SLATS ADAPTED TO PIVOT INTO AN OPEN POSITION WITH RESPECT TO SAID OPENINGS UNDER THE PRESSURE OF THROUGH FLOWING GAS AND TO RETURN TO A CLOSED POSITION WHEN THE PRESSURE OF THE GAS FALLS BELOW A PREDETERMINED MINIMUM LEVEL, EACH OF SAID SLATS BEING PIVOTABLE ABOUT AXIS PARALLEL TO THE LONGITUDINAL AXIS OF THE SLATS AND DISPLACED FROM THE POSITION OCCUPIED BY THE SLATS WHEN CLOSED, THE EDGES OF EACH SLAT BEING RESPECTIVELY ASSOCIATED WITH SEATINGS AGAINST WHICH THEY BEAR TIGHTLY WHEN CLOSED, EACH OF SAID SLATS HAVING AN ACTUATING LEVER ASSOCIATED THEREWITH, EACH OF SAID LEVERS HAVING AN ARM SECURED AT ONE END TO AN ASSOCIATED SLAT AND EXTENDING OUTWARDLY THEREFROM FORMING AN ACUTE ANGLE WITH RESPECT THERETO, SAID LEVER HAVING A SECOND ARM SECURED AT ONE END TO SAID FIRST ARM AND EXTENDING OUTWARDLY THEREFROM IN DIRECTION AT RIGHT ANGLES TO THE ASSOCIATED SLAT WHEN THE LATTER IS CLOSED, THE FREE END OF SAID SECOND ARM BEING PIVOTALLY MOUNTED TO THE FRAME TO DEFINE THE PIVOTAL MOUNT FOR THE ASSOCIATED SLAT, A CONTROL ROD EXTENDING PARALLEL TO THE FRAME, THE FREE END OF EACH OF SAID FIRST ARMS OF SAID LEVER BEING PIVOTALLY CONNECTED TO SAID CONTROL ROD AT SPACED POSITIONS ALONG ITS LENGTH AND A DISPLACEABLE ABUTMENT MEMBER IN THE PATH OF MOVEMENT OF ONE END OF SAID CONTROL ROD TO LIMIT THE MOVEMENT OF THE LATTER. 